Research

Our Brain Just Got a Whole Lot More Complicated

Sohan Shah


    While the brain looks like a messy gray mass of folded clay, it is actually partitioned into numerous specialized regions.  Some regions are excited by a familiar face, others by touching a hot stove, and others by feeling the brisk wind on a winter day.  These functional zones were originally codified by the German anatomist Dr. Korbinian Brodmann in 1909 based on histologic slide observations and have been gradually refined ever since.

    On July 20, 2016, a research team led by Dr. Matthew Glasser published a new map of our brain in Nature Magazine, titled “A multi-modal parcellation of human cerebral cortex”, which reveals almost one-hundred previously uncharacterized regions of the brain [4].  Although the new zones have been identified, scientists have not yet discovered the functions of the new regions.  According to Dr. Glasser, “This map you should think of as version 1.0.  There may be a version 2.0 as the data get better and more eyes look at the data. We hope the map can evolve as the science progresses.” [3].  

    In 2013, Dr. Glasser and his colleagues began using the Human Connectome Project’s (HCP) database of 1,200 volunteers to compare their functional MRI brain scans while the participants were performing a variety of functions: memory, attention, and language [2].  The HCP’s goal is to determine the specific neural pathways that underlie brain function and behavior by analyzing many different aspects of the brain simultaneously (e.g the architecture, function, connectivity or topography). The simultaneous analysis of neuronal data is what differentiates Dr. Glasser’s work from previous attempts to map the brain.  In the past, scientists could only compare one aspect of the brain, such as the architecture, function, connectivity or topography [1].  The combination of different types of data allowed for more regions to be determined.  

    For instance, the scientists looked deeper into the brain’s anatomy and discovered that in some regions the density of neurons was vastly different than in others. They also looked at myelin, the protective insulating substance that surrounds cells and speed up neuronal impulses. The amounts of myelin varied vastly from one region to another.   The scientists trained a computer to analyze the data from the human subject’s brains and find the key markers that differentiated each region. Surprisingly, the number of necessary markers were surprisingly few.  This meant that a computer could map an individual's brain in around seventy minutes. The final difference between the research of Dr. Glasser’s team and research of years past is that Dr. Glasser’s team analyzed the brain's entire breadth, unlike neuroscientists of past generations who looked at only aspect of the cerebral cortex [1].

    The Connectome map created by Dr. Glasser’s team contains 180 regions.  Of these, 83 were familiar zones and 97 were previously uncharacterized [2].  The new regions were formed either by reforming the boundaries of older zones or by partitioning larger regions into multiple smaller ones.  For instance, the dorsolateral prefrontal cortex, once thought to be one region, it is now known to contain twelve smaller ones.

    There are many important implications of this research, especially in healthcare.  According to CNN, as reported in Advisory Board, an organization dedicated to helping healthcare organizations improve performance, the research could be used for teaching neurosurgery students, or for helping to plan more detailed operations.  Scientists could also use the more detailed map to figure out how Alzheimer’s and other dementias affect the brain {3] [1].

    The next step in this research is to determine if the identified regions are actually separate areas.  This would mean analyzing gene expression of neurons in different regions.  “You can imagine going to these 180 regions, taking a punch of tissue, and seeing if you can really genetically differentiate them,” said Dr. David Kleinfeld, a neuroscientist at the University of California, San Diego.  According to the New York Times, experts believe that scientists will discover the the newly identified areas contain multiple smaller regions functioning together.  According to Dr. David C. Van Essen, a principal investigator with the Human Connectome Project at Washington University Medical School, “We shouldn’t expect miracles and easy answers, but we’re positioned to accelerate progress.”


References


  1. Glasser, M. F., Coalson, T. S., Robinson, E. C., Hacker, C. D., Harwell, J., Yacoub, E., . . . Essen, D. C. (2016, July 20). A multi-modal parcellation of human cerebral cortex [Abstract]. Nature,536(7615), 171-178. doi:10.1038/nature18933

  2. Scutti, S. (2016, July 20). Updated brain map identifies 97 new areas. Retrieved August 24, 2016, from http://www.cnn.com/2016/07/20/health/new-brain-map/

  3. Zimmer, C. (2016, July 20). Updated Brain Map Identifies Nearly 100 New Regions. Retrieved August 24, 2016, from http://www.nytimes.com/2016/07/21/science/human-connectome-brain-map.html?_r=0

  4. Scientists discover almost 100 new brain regions, with possible implications for Alzheimer's and more. (2016, July 22). Retrieved August 24, 2016, from https://www.advisory.com/daily-briefing/2016/07/22/100-new-brain-regions

Sohan Shah

Sohan Shah


In addition to being a founder of the IYNA, I am also an undergraduate student at Johns Hopkins University and majoring in neuroscience.